# BMW heating while engine 'Off' **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [December 18, 2009, 12:18pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375 "2009-12-18T12:18:27Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Onyx\_Z32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/onyx_z32/32/7581_2.png) [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)\ **Post date:** [December 18, 2009, 12:18pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/1 "2009-12-18T12:18:27Z")
_(… and after the motor is at operating temp, obviously.)_ I know I read somewhere in a manual that you can press the ‘MAX’ button (or some other button) after the vehicle is off and heat will blow into the cabin for up to 15 minutes. But now I can’t find that info anywhere. :gotme: I know I didn’t make this up, but I can’t find the exact instructions to know if I’m pressing the right button. Anyone know? I tried twice by pressing the ‘MAX’ button and air blows into the cabin, but it’s not that warm… ---
**Author:** ![LXIFLYBY](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/lxiflyby/32/7399_2.png) [@LXIFLYBY](https://forums.speedlife.net/u/LXIFLYBY)\ **Post date:** [December 18, 2009, 12:23pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/2 "2009-12-18T12:23:19Z")
thats a nice feature if its true ---
**Author:** ![newman](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/newman/32/7569_2.png) [@newman](https://forums.speedlife.net/u/newman)\ **Post date:** [December 18, 2009, 12:24pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/3 "2009-12-18T12:24:57Z")
The range rover, at least mine, has a mechanical waterpump, so IDK if that would really work… ---
**Author:** ![reliant\_turbo](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/reliant_turbo/32/7189_2.png) [@reliant\_turbo](https://forums.speedlife.net/u/reliant_turbo)\ **Post date:** [December 18, 2009, 12:28pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/4 "2009-12-18T12:28:37Z")
yeah you kind of have to have an electric waterpump to circulate the coolant through the block to the heater core as the heater core cools really fast when no additional hot coolant is circulated through it while the fan is blowing air across it. maybe it has a pump but its broken? maybe the system is supposed to use convection or it just doesnt perform as expected. Brian ---
**Author:** ![Onyx\_Z32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/onyx_z32/32/7581_2.png) [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)\ **Post date:** [December 18, 2009, 12:42pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/5 "2009-12-18T12:42:06Z")
> [@newman](#): > > The range rover, at least mine, has a mechanical waterpump, so IDK if that would really work… I know I read it in my manual, and King has it in his manual too. But now I can’t find it. I don’t know how this hocus-pocus magic works, lol. ---
**Author:** ![EvoMR](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/evomr/32/7186_2.png) [@EvoMR](https://forums.speedlife.net/u/EvoMR)\ **Post date:** [December 18, 2009, 12:54pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/6 "2009-12-18T12:54:04Z")
REST button? ---
**Author:** ![Viper966](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/viper966/32/7268_2.png) [@Viper966](https://forums.speedlife.net/u/Viper966)\ **Post date:** [December 18, 2009, 12:54pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/7 "2009-12-18T12:54:40Z")
mine has a “rest” button on the dash in the Heater area… im not sure what it does yet ---
**Author:** ![Onyx\_Z32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/onyx_z32/32/7581_2.png) [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)\ **Post date:** [December 18, 2009, 1:08pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/8 "2009-12-18T13:08:33Z")
I don’t have a REST button - my climate control is the same as the 6 series I think: ![http://blogs.cars.com/photos/uncategorized/landrover_dash2.jpg](http://blogs.cars.com/photos/uncategorized/landrover_dash2.jpg) ---
**Author:** ![EvoMR](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/evomr/32/7186_2.png) [@EvoMR](https://forums.speedlife.net/u/EvoMR)\ **Post date:** [December 18, 2009, 1:12pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/9 "2009-12-18T13:12:11Z")
> [@Viper966](#): > > mine has a “rest” button on the dash in the Heater area… im not sure what it does yet It does what Josh is talking about. Do a quick a google search. 🙂 ---
**Author:** ![Onyx\_Z32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/onyx_z32/32/7581_2.png) [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)\ **Post date:** [December 18, 2009, 1:17pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/10 "2009-12-18T13:17:42Z")
> [@EvoMR](#): > > It does what Josh is talking about. Do a quick a google search. 🙂 Ah think I found it: > If you car has a MAX button on the HVAC panel…it will do the same thing. It stands for RESIDUAL…meaning…after the car has warmed up to operating temps…and the ambient temp (outdoors) is 59F or below…you can press the REST button (or MAX) button and warmed air will blow into the cabin when the ignition is turned off. > > This is a way to keep the car warmed if you have to stop at a railroad crossing…or make small short trips to the store or bank etc…you can hit the REST or MAX button after turning the ignition off while you run in to take care of your business. ---
**Author:** ![Onyx\_Z32](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/onyx_z32/32/7581_2.png) [@Onyx\_Z32](https://forums.speedlife.net/u/Onyx_Z32)\ **Post date:** [December 18, 2009, 1:19pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/11 "2009-12-18T13:19:02Z")
![http://www.bimmerboard.com/members/q/original/MAX%20AIR%20Instructions.jpg](http://www.bimmerboard.com/members/q/original/MAX%20AIR%20Instructions.jpg) ---
**Author:** ![Matt\_Danger](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/matt_danger/32/4981_2.png) [@Matt\_Danger](https://forums.speedlife.net/u/Matt_Danger)\ **Post date:** [December 18, 2009, 1:24pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/12 "2009-12-18T13:24:04Z")
> [@newman](#): > > The range rover, at least mine, has a mechanical waterpump, so IDK if that would really work… Does it have an auxillary water pump? ---
**Author:** ![travisn](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/travisn/32/5046_2.png) [@travisn](https://forums.speedlife.net/u/travisn)\ **Post date:** [December 18, 2009, 2:05pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/13 "2009-12-18T14:05:15Z")
since the main issue is resolved I have this slightly OT question to ask… why dont cars come with electric heaters built into the HVAC system to provide heat before the engine is actually warmed up? ---
**Author:** ![Jeller](https://avatars.discourse-cdn.com/v4/letter/j/bc8723/32.png) [@Jeller](https://forums.speedlife.net/u/Jeller)\ **Post date:** [December 18, 2009, 2:07pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/14 "2009-12-18T14:07:24Z")
> [@EvoMR](#): > > REST button? Love the rest button, and it remembers you heated seat setting too, good stuff. ---
**Author:** ![Jim1234664](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/jim1234664/32/7438_2.png) [@Jim1234664](https://forums.speedlife.net/u/Jim1234664)\ **Post date:** [December 18, 2009, 2:11pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/15 "2009-12-18T14:11:25Z")
> [@travisn](#): > > since the main issue is resolved I have this slightly OT question to ask… > > why dont cars come with electric heaters built into the HVAC system to provide heat before the engine is actually warmed up? offhand I would say complexity/integration into the regular HVAC system and cost, possibly size since it would have to be somewhat large and most likely would be under the dash ---
**Author:** ![66impalass](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/66impalass/32/7429_2.png) [@66impalass](https://forums.speedlife.net/u/66impalass)\ **Post date:** [December 18, 2009, 2:28pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/16 "2009-12-18T14:28:33Z")
> [@travisn](#): > > since the main issue is resolved I have this slightly OT question to ask… > > why dont cars come with electric heaters built into the HVAC system to provide heat before the engine is actually warmed up? Current draw on even a small 3,4kw heater is astronomical on a 120V system, now just imagine it on a 12v system ---
**Author:** ![MPD47](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/mpd47/32/7383_2.png) [@MPD47](https://forums.speedlife.net/u/MPD47)\ **Post date:** [December 18, 2009, 3:40pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/17 "2009-12-18T15:40:29Z")
This has nothing to do with an electronic water pump all it is doing is running the hvac blower after the car is off at “full heat” blowing warm air off the heater core into the cabin. My e39 does it as well. ---
**Author:** ![16vCorvette](https://avatars.discourse-cdn.com/v4/letter/1/b487fb/32.png) [@16vCorvette](https://forums.speedlife.net/u/16vCorvette)\ **Post date:** [December 18, 2009, 4:28pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/18 "2009-12-18T16:28:16Z")
Interesting - my e39 has an electronic water pump on the fan shroud along with the mechanical water pump on the block. I didn’t check to see if the electric pump has a seperate circuit to the heater core. ---
**Author:** ![travisn](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/travisn/32/5046_2.png) [@travisn](https://forums.speedlife.net/u/travisn)\ **Post date:** [December 18, 2009, 5:11pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/19 "2009-12-18T17:11:34Z")
> [@MPD47](#): > > This has nothing to do with an electronic water pump all it is doing is running the hvac blower after the car is off at “full heat” blowing warm air off the heater core into the cabin. My e39 does it as well. there is no way the heater core would provide heat for very long without hot coolant going through it. my accord uses a hot water valve to control interior temp and if you shut the valve off (put it to cold) it instantly loses any heat… it has to keep circulating hot water somehow. ---
**Author:** ![Hass](https://avatars.discourse-cdn.com/v4/letter/h/51bf81/32.png) [@Hass](https://forums.speedlife.net/u/Hass)\ **Post date:** [December 18, 2009, 5:25pm UTC](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375/20 "2009-12-18T17:25:49Z")
> [@MPD47](#): > > This has nothing to do with an electronic water pump all it is doing is running the hvac blower after the car is off at “full heat” blowing warm air off the heater core into the cabin. My e39 does it as well. Uh. take a car without this feature, turn it off, then turn the key to ON… without starting it. so that the heater fan blows. it will be warm for about 2 seconds. then blow ice cold air. becaaauussee the coolant in the heater core has been chilled? or i don’t know. but that’s why i thought it gets cold 😛 and it can’t really move… [Next page](https://forums.speedlife.net/t/bmw-heating-while-engine-off/77375.md?page=2)